I'm nearly finished reading "The Trouble With Physics" by Lee Smolin. Not technical but very clearly written for the layman on the state of theoretical physics and why he thinks there are problems with the directions being taken. His treatment of String Theory is very readable and interesting and much less hardwork than Brian Greene's!

I think that might be a little bit of a quantum leap "up" from the usual introductory text. You have to be quiet determined to plough through the axioms surrounding the proofs. It doesnt let you off the hook either, if you miss a step in logic then it all becomes a bit intractable.
A tough read...

The Fabric Of Reality by David Deutsch is a remarkable book, but it's now years since I read it and can't remember precisely what his point was. But it ties together the many-worlds interpretation of quantum mechanics with Turing's ideas about computation, some vaguely Popperian philosophy and something else, and makes it seem like a completely revolutionary new description of reality itself (it's about more than just what the universe 'out there' is like). I'd love to read it again in fact, maybe a bit more would stick second time round.

In reply to Jon Stewart: So nobody really has managed Francis Fukuyama's 'The End of History and The Last Man' Shame I was going to ask for advice on how hard going this 'definitive' book is and whether I should try again with my pristine hardbook copy.